1. Field of the Invention
The present invention relates to a technology for saving the power consumption of a server system.
2. Description of the Related Art
Recently, enhancement of server capacity is resulting in a significant rise in power consumption of servers. Especially, so called blade servers have higher central processing unit (CPU) density than the so called rack mount servers, so that the blade servers consume higher power. Therefore, in places such as the so called Internet Data Centers (IDC's), which includes many blade servers, a power layout is carried out to ensure that sufficient power is supplied.
However, recently, increasingly high performing CPU's are used in the servers and multiple such CPU's are mounted on a single server. Sometimes the required amount of power can exceed the estimated amount of power in the original power layout. To avoid this, it becomes necessary to restrict the number of servers mounted on a rack.
Further, as the temperature tends to build at some places depending on the placement of the servers or the air-conditioning, it is necessary to control power consumption by reducing the number of servers mounted on the rack taking into account the temperature.
Thus, when there is a restriction on the power that is supplied to the server system, generally solution is sought by reducing the number of servers or installing servers that consume less power. Unfortunately, these measures compromise the servers' processing capacity.
Japanese Patent Laid-Open Publication No. 2005-202506 discloses a method for controlling power consumption by each server blade by adding hardware called blade management controller (BMC) to a server blade in a blade server system.
However, the conventional tactics, such as reducing the number of servers or installing servers that consume less power, adversely affect the processing capacity of the server system. To counter the problem, the power design of the entire server system will need to be overhauled. However, this solution is not practical as overhauling the power design also affects parts that are not involved in higher power consumption.
The power consumption of the blade server system can be curtailed by managing the power consumption per server blade in the blade server system. However, the power consumption of the entire server system that includes rack-mounted servers cannot be controlled.
Thus, there is need of a technology that can reduce the power consumption of a server system without compromising the processing capacity of the server system.